1. Field of the Invention
This invention relates to a composition containing an extract obtained by extraction with a water-containing organic solvent, which has a high bioavailability and can be formulated into various preparations including tablets, granules, powder preparations, drinkable preparations, and syrups, and also to a process for preparing said composition.
2. Prior art
In France, Germany, etc., remedial preparations containing, as active ingredient, an extract obtained from plant tissues such as ginkgo leaves by extraction with a water-containing organic solvent have hitherto been used widely for the purpose of improving metabolism of cerebral circulation.
It is known that the above extract obtained by extraction with a water-containing organic solvent has such pharmacological actions as relaxation of smooth muscles of blood vessels contracted owing to stress, tension, etc., thereby reducing resistance in peripheral arteries and cerebral circulatory system; and vasodilation and increasing of blood flow velocity, thereby increasing blood flow in the pacillary tissues. Said extract is also known to have a pharmacological action of lowering viscosity of the blood in the arteries and veins, thereby smoothing the blood flow, with the result that disorder in the peripheral blood vessels and cerebral blood vessels is improved.
In order to administer the above extract obtained by extraction with a water-containing organic solvent to elderly people, or minors, or to patients with liver diseases, it is desirable to formulate it into preparations not containing ethanol. That is to say, it is necessary to formulate it into solid preparations including tablets, granules, and powder preparations, or liquid preparations such as drinkable preparations and syrups, in such a way that no ethanol is used, yet the extract contained is well absorbed through the digestive tract.
However, the above-mentioned extract obtained by extraction with a water-containing organic solvent has such property that it is soluble in water-containing organic solvents such as water-containing acetone, water-containing methyl ethyl ketone, water-containing methanol and water-containing ethanol, but practically insoluble in water. Thus, it is possible to formulate the extract into liquid preparations such as tinctures, spirits, and elixirs, as ethanol is used in these preparations as one of the solvents.
However, it has been impossible to formulate it into non-alcoholic liquid preparations such as non alcoholic drinkable preparations and syrups.
When the above extract obtained by extraction with a water-containing organic solvent is used in easy-to-take solid preparations such as tablets, granules and powder preparations, the absorption becomes poor. The reason is that, to have the active ingredients of the extract absorbed into the human body, it is necessary for the active ingredients to be dissolved or emulsified in the digestive tract.
In making this invention, the above problems were taken into consideration, and thus the purpose of this invention is to provide a composition which contains an extract obtained by extraction with a water-containing organic solvent and which has a high bioavailability and can be formulated into various forms of preparations including tablets, granules, powder preparations, drinkable preparations and syrups.
Another purpose of this invention is to provide a process for preparing said composition containing an extract obtained by extraction with a water-containing organic solvent.